1. Field of the Invention
The invention relates to a vehicle seat.
2. Description of the Related Art
A vehicle seat typically includes a pad and a trim cover for covering the pad. The trim cover is formed by sewing multiple skin pieces. For example, a trim cover for covering a pad of a seat cushion includes, as the skin piece thereof, a body for covering the seat surface of the pad and a gore for covering the side surfaces of the pad (see, for example, JP-UM-A-S59-75351).
The gore is also applied to covering the surface of the step portion of the pad. A vehicle seat 61 shown in FIG. 8 is a seat to be installed on the passenger seat side of the rear of a vehicle. A seat back 63 includes an auxiliary seat back 63a formed integrally therewith which is to be interposed between the seat back 63 and a driver's seat side seat (not shown). In the auxiliary seat back 63a, there is stored a pull-out type armrest 65 tiltable toward to the seat cushion side.
As shown in FIG. 9, a pad 66 of the seat back 63 includes a first pad part 71 and a second pad part 72 disposed adjacent to the first pad part 72. The second pad part 72 constitutes a pad of the auxiliary seat back 63a (see FIG. 8), while the first pad part 71 constitutes a pad of the seat back 63 (see FIG. 8) except for the auxiliary seat back 63a. The first and second pads 71 and 72 are integrally formed. The upper end of the second pad part 72 is positioned lower than the upper end of the first pad part 71 and is formed concave with respect to the upper end of the first pad part 71; and, a step portion 73 is formed along at least a part of the boundary between the upper ends of the first and second pad parts 71 and 72.
A trim cover 67 of the vehicle seat 61 integrally covers the first and second pads 71 and 72 and includes, as the skin pieces thereof, a first body 67a for covering the upper end face of the first pad part 71 following the surface of the step portion 73, a second body 67c for covering the upper end face of the second pad part 72 following the surface of the step portion 73, and a gore 67b jointed to the first and second bodies 67a and 67c for covering the surface of the step portion 73.
In the vehicle seat 61 shown in FIGS. 8 and 9, a seam allowance 68a between the first body 67a and gore 67b of the trim cover 67 and a seam allowance 68b between the second body 67c and gore 67c are both brought down on the gore 67b side and are superimposed on the surface of the step portion 73.
The step height H of the step portion 73 is set, for example, according to a seat design. When the width of the seam allowances 68a and 68b with respect to the step height H is excessively large, the seam allowances 68a and 68b are superimposed on each other on the surface of the step portion 73. For example, supposing the width of the seam allowances 68a and 68b is typically set to 7˜8 mm in consideration of the workability or the like of sewing, when the step height H is 15 mm or less, the seam allowances 68a and 68b are superimposed on each other on the surface of the step portion 73. When the seam allowances 68a and 68b are superimposed, there is a fear that wrinkles or sags can occur in the gore 67b covering the seam allowances 68a and 68b, thereby impairing the appearance of the vehicle seat 61.
There is a limit to reducing the width of the seam allowances 68a and 68b and, due to this, reduction of the step height H of the step portion 73 is also restricted, thereby restricting the design of the seat.